package objects

import "image"
import "git.tebibyte.media/tomo/tomo"
import "git.tebibyte.media/tomo/tomo/text"
import "git.tebibyte.media/tomo/tomo/input"
import "git.tebibyte.media/tomo/tomo/event"

// TextInput is a single-line editable text box.
type TextInput struct {
	tomo.TextBox
	text []rune
	on struct {
		valueChange event.FuncBroadcaster
		confirm     event.FuncBroadcaster
	}
}

// NewTextInput creates a new text input containing the specified text.
func NewTextInput (text string) *TextInput {
	this := &TextInput { TextBox: tomo.NewTextBox() }
	this.SetRole(tomo.R("objects", "TextInput"))
	this.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
	this.SetAttr(tomo.AOverflow(true, false))
	this.SetText(text)
	this.SetFocusable(true)
	this.SetSelectable(true)
	this.OnKeyDown(this.handleKeyDown)
	this.OnKeyUp(this.handleKeyUp)
	this.OnScroll(this.handleScroll)
	return this
}

// SetText sets the text content of the input.
func (this *TextInput) SetText (text string) {
	this.text = []rune(text)
	this.TextBox.SetText(text)
}

// Text returns the text content of the input.
func (this *TextInput) Text () string {
	return string(this.text)
}

// OnConfirm specifies a function to be called when the user presses enter
// within the text input.
func (this *TextInput) OnConfirm (callback func ()) event.Cookie {
	return this.on.confirm.Connect(callback)
}

// OnValueChange specifies a function to be called when the user edits the input
// text.
func (this *TextInput) OnValueChange (callback func ()) event.Cookie {
	return this.on.valueChange.Connect(callback)
}

// Type types a character at the current dot position.
func (this *TextInput) Type (char rune) {
	dot := this.Dot()
	this.text, dot = text.Type(this.text, dot, rune(char))
	this.Select(dot)
	this.SetText(string(this.text))
}

func (this *TextInput) handleKeyDown (key input.Key, numpad bool) bool {
	dot       := this.Dot()
	modifiers := this.Window().Modifiers()
	word      := modifiers.Control
	changed   := false

	defer func () {
		this.Select(dot)
		if changed {
			this.SetText(string(this.text))
			this.on.valueChange.Broadcast()
		}
	} ()

	switch {
	case key == input.KeyEnter:
		this.on.confirm.Broadcast()
		return true
	case key == input.KeyBackspace:
		this.text, dot = text.Backspace(this.text, dot, word)
		changed = true
		return true
	case key == input.KeyDelete:
		this.text, dot = text.Delete(this.text, dot, word)
		changed = true
		return true
	case key == input.Key('a') && modifiers.Control:
		dot.Start = 0
		dot.End   = len(this.text)
		return true
	case key.Printable():
		this.text, dot = text.Type(this.text, dot, rune(key))
		changed = true
		return true
	default:
		return false
	}
}

func (this *TextInput) handleKeyUp (key input.Key, numpad bool) bool {
	modifiers := this.Window().Modifiers()
	switch {
	case key == input.KeyEnter:
		return true
	case key == input.KeyBackspace:
		return true
	case key == input.KeyDelete:
		return true
	case key == input.Key('a') && modifiers.Control:
		return true
	case key.Printable():
		return true
	default:
		return false
	}
}

func (this *TextInput) handleScroll (x, y float64) bool {
	if x == 0 { return false }
	this.ScrollTo(this.ContentBounds().Min.Sub(image.Pt(int(x), int(y))))
	return true
}